It gets cold in caves around the Mediterranean, too. My point was that if you could brew beer in the Middle East, you could brew it in Rome.
Purely cultural. Romans regarded beer as the drink of barbarians, and so any Roman worth his salt drank wine. Beer was more of a foodstuff. As for Egyptian beer: In Diocletian’s Edict of Prices, Egyptian beer was valued at considerably less than anybody elses. That must be some reflection on it’s quality.
It explains the lack of an economic motive to drive consumption. We know there was some consumption; your question (and presumably the OP’s) is why there wasn’t more consumption. Well, they were coming out of a wine-centric culture, and people tend to be very conservative about food. You can buy fish sauce, or whole dried peppers, or goat meat, or beef tripe, in any decently-sized American supermarket, and yet most Americans don’t eat these items on a regular basis, if at all. You can buy cheese in most Chinese cities, but to this day I know young people recently immigrated from China who think cheese is weird and disgusting. Romans put a fair amount of effort into convincing neighboring barbarians to drink (imported Roman) wine; there wasn’t any corresponding effort to get Romans to drink beer, and the areas where beer drinking seems to have been somewhat more common are largely those that most probably had a hard time getting adequate supplies of wine (off the major trade routes in areas with poor grape production potential).
First of all, I think Tevye made is rounds in a climate that was not Mediterranean (even if his traditions came from a Mediterranean place).
But more importantly, milk souring was definitely an issue for Ancient Romans (as well as every other pre-refrigeration culture). I mean, Italian cuisine is, I think, better known for its use of cheese than for its use of raw milk. I’m not sure Roman city dwellers really did consume much raw milk.
And true, bread goes bad as well, but it’s a lot easier to consistently make bread in a hot climate than beer (and, speaking of Italian cuisine, I have this feeling that they might have famously come up with a way to consume wheat flour that is more shelf-stable than bread… )
Sure, the Romans could have set up a system to brew beer, like bakeries but with more wastage and loss and the need for a deep cellar or other cool room, and maybe they did to some extent, but why would they base alcohol consumption around beer when wine was a superior technology for alcohol production, storage and shipment?